Journal of Applied Physiology, Vol 80, Issue 6 1898-1902, Copyright © 1996 by American Physiological Society
Analysis of diaphragm EMG signals: comparison of gating vs. subtraction for removal of ECG contamination
A. Bartolo, C. Roberts, R. R. Dzwonczyk and E. Goldman
Biomedical Engineering Center, Ohio State University, Columbus, USA.
The diaphragm electromyogram (EMGdi) conveys information relating to the
mechanisms of respiration; however, electrocardiogram (ECG) contamination
can compromise the accuracy of data derived from this signal. We examine
the EMGdi recorded from anesthetized spontaneously breathing dogs via
implanted electrodes to assess the extent of the error introduced by the
ECG contamination and the effectiveness of ECG gating in reducing this
error. Because ECG subtraction has been shown to generate accurate results
for such applications, it is used as the gold standard. Analysis of
variance methods are employed to compare results derived from the EMGdi
data after ECG subtraction with corresponding results derived from the
original data and from the data after ECG gating. Estimates of EMGdi
variables obtained by using subtraction and gating techniques were not
significantly different, indicating that gating can be employed on these
signals to reduce ECG contamination without affecting the accuracy of the
derived data. Results also show that at EMG-to-ECG power ratios > 13.3
dB, ECG contamination does not significantly affect estimates of the EMGdi
variables.
